Gas pressure operated thruster



p 22, 1964 s. J. KENT 3,149,457

GAS PRESSURE OPERATED THRUSTER Filed Aug. 29, 1963 Q h p, 8 9 \4 \Q/ 7\8N L h 3 9 N INVENTOR.

STANLEY J- KEN ATTORNEY5.

United States Patent ice 3,143,457 GAS PRESSURE OPERATED THRUSTER tanleyJ. Kent, Philadelphia, Pa, assignor te the United States of America asrepresented by the Secretary of the Army Filed Aug. 29, 1963, Ser. No.305,562 1 Claim. (Cl. 6tl26.1) (Granted under Title 35, US. Code (1952),see. 266) The invention described herein may be manufactured and used byor for the Government for governmental purposes without the payment tome of any royalty thereon.

This invention relates to thrusters of the type wherein a piston,coupled to a load device, is moved in a cylinder by gas pressureresulting from the firing of an explosive cartridge. It provides animproved thruster including means whereby the cartridge is firmly seatedat the time it is fired and the cartridge case is thereafter utilized tounlock the piston from the cylinder.

This improved thruster is similar in several respects to that of acopending application of Albert M. Stott, Serial No. 173,593, filedFebruary 15, 1962, for Thruster, now Patent No. 3,133,408, issued May19, 1964. It differs from the thruster of the aforesaid application inthat (1) the gas pressure utilized to actuate the firing pin is alsoutilized to firmly seat the cartridge at the time it is fired, and (2)the gas generated by the firing of the cartridge is utilized both tomove the cartridge case in a manner to unlock the pitson from thecylinder and to move the piston.

Where the cartridge is held in position by a threaded connection,vibration, such as that incident to the operation of aircraft, can causeloosening of the thread. A loosely seated cartridge absorbs energy andreduces the effective energy of the firing pin. This can result inignition failure. The present invention avoids this difficulty by meansincluding a hollow cylindrical member or barrel which (1) functions as afiring pin guideway, (2) is pressed against the cartridge by the samegas pressure that actuates the firing pin, and (3) is actuated by thegas generated by the firing of the cartridge to move the cartridge casein a manner to unlock the piston from the cylinder out of which it isthereafter driven.

The invention will be better understood from the following descriptionwhen considered in connection with the accompanying drawings and itsscope is indicated by the appended claim.

Referring to the drawings:

FIG. 1 is an end view of the thruster, and

FIG. 2 is a sectional view taken along the line 2-2 of FIG. 1.

The thruster illustrated by these figures includes a cylinder onto oneend of which is threaded a trunnion-cap 11 having a gas inlet 12. Ahollow piston 13 is movable in and extensible from the cylinder 10. Thispiston is closed at its outer end 14, is spaced from the cylinder toform an annular recess 15, has orifices 16 opening from the interior ofthe piston into the recess 15, and has a cartridge 17 positioned in itsinner end. For some purposes it may also enclose a propellant charge 18which is ignited by the firing of the cartridge.

The cartridge 17 has a large diameter section 19 and a Patented Sept.22, 1964 small diameter section 2.0. In the illustrated position of thecartridge, the large diameter section functions to maintain keys 21 inan internal groove of the cylinder 16 thereby interlocking the cylinderand the piston. When the case of the cartridge is moved rearward ashereinafter explained, the small diameter section 26 is brought intoregistry with the keys 21 and the piston is released from the cylinder.

interlinked with the cartridge 17 is a barrel 22 which is biased againstthe cartridge by a spring 23 and is releasably coupled to a firing pin24 by a shear pin 25. For preventing gas leakage, the firing pin 24 hasan O- ring 26, while barrel 22 has O-ring 27 and backup ring 23 andcylinder 10 has O-ring 29 and backup ring 31).

In the operation of the above described thruster, a gas pressure appliedthrough the inlet 12 forces the barrel 22 against the cartridge 17,shears the pin 25 and drives the firing pin 24 against the percussionprimer of the cartridge. The firing of the cartridge generates a gaspressure within the piston and fires the charge 18 if utilized. Theresulting gas pressure is applied through the orifices 16 and the recess15 to the forward end of the barrel 22. As a result the barrel movesrearward carrying with the case of the cartridge 17. At a certain pointin this rearward movement, the small diameter section 20 comes intoregistry with the keys 21 and the piston is released from the cylinder.The propellant 18 may be incorporated in the cartridge 17 when thevolume of the cartridge is compatible with the thrust and propellantrequirements.

I claim:

The combination of a cylinder having an internal groove,

a hollow piston movable in said cylinder and extensible therefrom, theforward end of said piston being closed and said piston being spacedfrom said cylinder to form therebetween an annular recess closed at itsforward end by an internal flange of said cylinder,

means formnig a passageway between the interior of said piston and saidrecess,

a cartridge positioned in the rearward end of said piston and havingsmall and large diameter sections, locking means extending from saidlarge diameter section through said piston into said internal groove,

a floating barrel interlinked with said cartridge and movable in saidcylinder,

a spring urging said barrel and said cartridge against the rearward endof said piston, and

means for firing said cartridge whereby there is produced a gas pressureextending from said piston through said passageway and said recess tosaid barrel and said barrel is forced against the tension of said springto move said small diameter section into alinement with said lockingmeans and release said piston from said cylinder.

References Cited in the file of this patent UNITED STATES PATENTS

